1 /*
2 * Copyright 2009 The Android Open Source Project
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8
9 #include "SkColorPriv.h"
10
11 /*
12 Filter_32_opaque
13
14 There is no hard-n-fast rule that the filtering must produce
15 exact results for the color components, but if the 4 incoming colors are
16 all opaque, then the output color must also be opaque. Subsequent parts of
17 the drawing pipeline may rely on this (e.g. which blitrow proc to use).
18 */
19
Filter_32_opaque(unsigned x,unsigned y,SkPMColor a00,SkPMColor a01,SkPMColor a10,SkPMColor a11,SkPMColor * dstColor)20 static inline void Filter_32_opaque(unsigned x, unsigned y,
21 SkPMColor a00, SkPMColor a01,
22 SkPMColor a10, SkPMColor a11,
23 SkPMColor* dstColor) {
24 SkASSERT((unsigned)x <= 0xF);
25 SkASSERT((unsigned)y <= 0xF);
26
27 int xy = x * y;
28 const uint32_t mask = 0xFF00FF;
29
30 int scale = 256 - 16*y - 16*x + xy;
31 uint32_t lo = (a00 & mask) * scale;
32 uint32_t hi = ((a00 >> 8) & mask) * scale;
33
34 scale = 16*x - xy;
35 lo += (a01 & mask) * scale;
36 hi += ((a01 >> 8) & mask) * scale;
37
38 scale = 16*y - xy;
39 lo += (a10 & mask) * scale;
40 hi += ((a10 >> 8) & mask) * scale;
41
42 lo += (a11 & mask) * xy;
43 hi += ((a11 >> 8) & mask) * xy;
44
45 *dstColor = ((lo >> 8) & mask) | (hi & ~mask);
46 }
47
Filter_32_alpha(unsigned x,unsigned y,SkPMColor a00,SkPMColor a01,SkPMColor a10,SkPMColor a11,SkPMColor * dstColor,unsigned alphaScale)48 static inline void Filter_32_alpha(unsigned x, unsigned y,
49 SkPMColor a00, SkPMColor a01,
50 SkPMColor a10, SkPMColor a11,
51 SkPMColor* dstColor,
52 unsigned alphaScale) {
53 SkASSERT((unsigned)x <= 0xF);
54 SkASSERT((unsigned)y <= 0xF);
55 SkASSERT(alphaScale <= 256);
56
57 int xy = x * y;
58 const uint32_t mask = 0xFF00FF;
59
60 int scale = 256 - 16*y - 16*x + xy;
61 uint32_t lo = (a00 & mask) * scale;
62 uint32_t hi = ((a00 >> 8) & mask) * scale;
63
64 scale = 16*x - xy;
65 lo += (a01 & mask) * scale;
66 hi += ((a01 >> 8) & mask) * scale;
67
68 scale = 16*y - xy;
69 lo += (a10 & mask) * scale;
70 hi += ((a10 >> 8) & mask) * scale;
71
72 lo += (a11 & mask) * xy;
73 hi += ((a11 >> 8) & mask) * xy;
74
75 lo = ((lo >> 8) & mask) * alphaScale;
76 hi = ((hi >> 8) & mask) * alphaScale;
77
78 *dstColor = ((lo >> 8) & mask) | (hi & ~mask);
79 }
80
81 // Two color version, where we filter only along 1 axis
Filter_32_opaque(unsigned t,SkPMColor color0,SkPMColor color1,SkPMColor * dstColor)82 static inline void Filter_32_opaque(unsigned t,
83 SkPMColor color0,
84 SkPMColor color1,
85 SkPMColor* dstColor) {
86 SkASSERT((unsigned)t <= 0xF);
87
88 const uint32_t mask = 0xFF00FF;
89
90 int scale = 256 - 16*t;
91 uint32_t lo = (color0 & mask) * scale;
92 uint32_t hi = ((color0 >> 8) & mask) * scale;
93
94 scale = 16*t;
95 lo += (color1 & mask) * scale;
96 hi += ((color1 >> 8) & mask) * scale;
97
98 *dstColor = ((lo >> 8) & mask) | (hi & ~mask);
99 }
100
101 // Two color version, where we filter only along 1 axis
Filter_32_alpha(unsigned t,SkPMColor color0,SkPMColor color1,SkPMColor * dstColor,unsigned alphaScale)102 static inline void Filter_32_alpha(unsigned t,
103 SkPMColor color0,
104 SkPMColor color1,
105 SkPMColor* dstColor,
106 unsigned alphaScale) {
107 SkASSERT((unsigned)t <= 0xF);
108 SkASSERT(alphaScale <= 256);
109
110 const uint32_t mask = 0xFF00FF;
111
112 int scale = 256 - 16*t;
113 uint32_t lo = (color0 & mask) * scale;
114 uint32_t hi = ((color0 >> 8) & mask) * scale;
115
116 scale = 16*t;
117 lo += (color1 & mask) * scale;
118 hi += ((color1 >> 8) & mask) * scale;
119
120 lo = ((lo >> 8) & mask) * alphaScale;
121 hi = ((hi >> 8) & mask) * alphaScale;
122
123 *dstColor = ((lo >> 8) & mask) | (hi & ~mask);
124 }
125